Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium
The Southern Hemisphere westerly winds influence the spatial distribution of precipitation in southern South America and play a significant role in the global carbon cycle, yet little is known about how this important atmospheric circulation feature has varied in the past. Here, we present a sedimen...
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Online Access: | https://doi.org/10.1016/j.quascirev.2008.03.006 http://www.captura.uchile.cl/handle/2250/7014 |
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ftunivchilecap:oai:www.captura.uchile.cl:2250/7014 2023-05-15T13:43:13+02:00 Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium Moy, Christopher M. Dunbar, Robert B. Moreno, Patricio I. Francois, Jean-Pierre Villa Martínez, Rodrigo Mucciarone, David M. Guilderson, Thomas P. Garreaud, René 2008-07 https://doi.org/10.1016/j.quascirev.2008.03.006 http://www.captura.uchile.cl/handle/2250/7014 en eng PERGAMON-ELSEVIER SCIENCE LTD SOUTHERN-HEMISPHERE CARBON ISOTOPES ORGANIC-MATTER MARINE-SEDIMENTS CLIMATE-CHANGE ICE-AGE LAKE GROWTH PALEOCLIMATE AMERICA Artículo de Revista 2008 ftunivchilecap https://doi.org/10.1016/j.quascirev.2008.03.006 2013-12-20T10:23:52Z The Southern Hemisphere westerly winds influence the spatial distribution of precipitation in southern South America and play a significant role in the global carbon cycle, yet little is known about how this important atmospheric circulation feature has varied in the past. Here, we present a sediment core record of late Holocene variability from Lago Guanaco, a small closed-basin lake located in Torres del Paine National Park, Chilean Patagonia. The park is located in the core of the modern wind field and variations in the intensity of the atmospheric circulation directly influence the hydrology of this region. We combine stable isotopic measurements of biogenic carbonate and bulk organic matter to identify two periods of increased evaporation between 900-550 and similar to 400-50 calendar years before present (cal yr BP). The first interval is coincident with the Medieval Climate Anomaly (MCA) while the more recent period is broadly coincident with the timing of the Little Ice Age (LIA). During the LIA interval, we observe simultaneous monotonic increases in the delta O-18 of biogenic carbonate and Nothofagus dombeyi-type pollen, which we interpret as indicative of significant changes in the intensity of the southern westerlies during the last millennium. The isotopic and palynological variations in the Guanaco record are coincident with geochemical variations found in an Antarctic ice core record from Siple Dome, suggesting that the signal preserved in Lago Guanaco is regional rather than local, and that the LIA intensification was accompanied by a poleward shift in the southern margin of the westerlies. In addition, we interpret four periods of increased lake productivity centered on 900, 650, 500, and 200 cal yr BP from simultaneous increases in the delta C-13 of bulk organic material and biogenic carbonate. These increases in lake productivity are most likely tied to increases in summer temperatures. Article in Journal/Newspaper Antarc* Antarctic ice core Universidad de Chile: Captura Age Lake ENVELOPE(-97.607,-97.607,56.000,56.000) Antarctic Basin Lake ENVELOPE(161.917,161.917,-76.150,-76.150) Paine ENVELOPE(-147.533,-147.533,-86.767,-86.767) Patagonia Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Dome ENVELOPE(-148.833,-148.833,-81.667,-81.667) Quaternary Science Reviews 27 13-14 1335 1349 |
institution |
Open Polar |
collection |
Universidad de Chile: Captura |
op_collection_id |
ftunivchilecap |
language |
English |
topic |
SOUTHERN-HEMISPHERE CARBON ISOTOPES ORGANIC-MATTER MARINE-SEDIMENTS CLIMATE-CHANGE ICE-AGE LAKE GROWTH PALEOCLIMATE AMERICA |
spellingShingle |
SOUTHERN-HEMISPHERE CARBON ISOTOPES ORGANIC-MATTER MARINE-SEDIMENTS CLIMATE-CHANGE ICE-AGE LAKE GROWTH PALEOCLIMATE AMERICA Moy, Christopher M. Dunbar, Robert B. Moreno, Patricio I. Francois, Jean-Pierre Villa Martínez, Rodrigo Mucciarone, David M. Guilderson, Thomas P. Garreaud, René Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium |
topic_facet |
SOUTHERN-HEMISPHERE CARBON ISOTOPES ORGANIC-MATTER MARINE-SEDIMENTS CLIMATE-CHANGE ICE-AGE LAKE GROWTH PALEOCLIMATE AMERICA |
description |
The Southern Hemisphere westerly winds influence the spatial distribution of precipitation in southern South America and play a significant role in the global carbon cycle, yet little is known about how this important atmospheric circulation feature has varied in the past. Here, we present a sediment core record of late Holocene variability from Lago Guanaco, a small closed-basin lake located in Torres del Paine National Park, Chilean Patagonia. The park is located in the core of the modern wind field and variations in the intensity of the atmospheric circulation directly influence the hydrology of this region. We combine stable isotopic measurements of biogenic carbonate and bulk organic matter to identify two periods of increased evaporation between 900-550 and similar to 400-50 calendar years before present (cal yr BP). The first interval is coincident with the Medieval Climate Anomaly (MCA) while the more recent period is broadly coincident with the timing of the Little Ice Age (LIA). During the LIA interval, we observe simultaneous monotonic increases in the delta O-18 of biogenic carbonate and Nothofagus dombeyi-type pollen, which we interpret as indicative of significant changes in the intensity of the southern westerlies during the last millennium. The isotopic and palynological variations in the Guanaco record are coincident with geochemical variations found in an Antarctic ice core record from Siple Dome, suggesting that the signal preserved in Lago Guanaco is regional rather than local, and that the LIA intensification was accompanied by a poleward shift in the southern margin of the westerlies. In addition, we interpret four periods of increased lake productivity centered on 900, 650, 500, and 200 cal yr BP from simultaneous increases in the delta C-13 of bulk organic material and biogenic carbonate. These increases in lake productivity are most likely tied to increases in summer temperatures. |
format |
Article in Journal/Newspaper |
author |
Moy, Christopher M. Dunbar, Robert B. Moreno, Patricio I. Francois, Jean-Pierre Villa Martínez, Rodrigo Mucciarone, David M. Guilderson, Thomas P. Garreaud, René |
author_facet |
Moy, Christopher M. Dunbar, Robert B. Moreno, Patricio I. Francois, Jean-Pierre Villa Martínez, Rodrigo Mucciarone, David M. Guilderson, Thomas P. Garreaud, René |
author_sort |
Moy, Christopher M. |
title |
Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium |
title_short |
Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium |
title_full |
Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium |
title_fullStr |
Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium |
title_full_unstemmed |
Isotopic evidence for hydrologic change related to the westerlies in SW Patagonia, Chile, during the last millennium |
title_sort |
isotopic evidence for hydrologic change related to the westerlies in sw patagonia, chile, during the last millennium |
publisher |
PERGAMON-ELSEVIER SCIENCE LTD |
publishDate |
2008 |
url |
https://doi.org/10.1016/j.quascirev.2008.03.006 http://www.captura.uchile.cl/handle/2250/7014 |
long_lat |
ENVELOPE(-97.607,-97.607,56.000,56.000) ENVELOPE(161.917,161.917,-76.150,-76.150) ENVELOPE(-147.533,-147.533,-86.767,-86.767) ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-148.833,-148.833,-81.667,-81.667) |
geographic |
Age Lake Antarctic Basin Lake Paine Patagonia Siple Siple Dome |
geographic_facet |
Age Lake Antarctic Basin Lake Paine Patagonia Siple Siple Dome |
genre |
Antarc* Antarctic ice core |
genre_facet |
Antarc* Antarctic ice core |
op_doi |
https://doi.org/10.1016/j.quascirev.2008.03.006 |
container_title |
Quaternary Science Reviews |
container_volume |
27 |
container_issue |
13-14 |
container_start_page |
1335 |
op_container_end_page |
1349 |
_version_ |
1766185970410979328 |